A metal matrix composite (MMC) is composite material with at least two constituent parts, one being a metal. The other material may be a different metal or a non-metal material, such as a ceramic. MMCs are made by dispersing a reinforcing material into a metal matrix. The matrix is the monolithic material into which the reinforcement is embedded. In structural applications, the matrix is usually a lighter metal such as aluminum, magnesium, or titanium, and provides a compliant support for a reinforcement material. The reinforcement material is embedded into the matrix. The reinforcement material does not always serve a purely structural task (i.e., reinforcing the MMC), but can also change physical properties such as a wear resistance, friction coefficient, or thermal conductivity of the MMC. The reinforcement material can be either continuous, or discontinuous. Discontinuous MMCs can be isotropic, and can be worked with standard metalworking techniques, such as extrusion, forging or rolling. In addition, they may be machined using conventional techniques, but commonly would need the use of polycrystalline diamond tooling (PCD).
What is desired is a metal matrix composite that presents a cosmetically appealing appearance that is maintained throughout an operating lifetime and is relatively inexpensive to manufacture in both processing and materials.